/Engine/Plugins/FX/Niagara/Source/NiagaraEditor/Public/ViewModels/NiagaraSystemViewModel.h
Resets the System instance to initial conditions on the next tick. Tries to resets system simulation time. Does not reset all systems that share its emitters. Does not reinitialize the system to pull in changes. Calls into overloadedResetSystem().
void RequestResetSystem()